Messages in this thread |  | | Subject | Re: [PATCH] irq-gic-v3: fix NULL dereference of disabled redist_base | From | Guoheyi <> | Date | Tue, 17 Dec 2019 09:20:12 +0800 |
| |
在 2019/12/16 22:23, Marc Zyngier 写道: > On 2019-12-16 13:50, Guoheyi wrote: >> 在 2019/12/16 19:14, Marc Zyngier 写道: >>> Hi Heyi, >>> >>> On 2019-12-16 06:27, Heyi Guo wrote: >>>> If we use ACPI MADT GICC structure to pass single redistributor base, >>>> and mark some GICC as disabled, we'll get below call trace during >>>> boot: >>>> >>>> [ 0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 >>>> [ 0.000000] GICv3: 256 SPIs implemented >>>> [ 0.000000] GICv3: 0 Extended SPIs implemented >>>> [ 0.000000] GICv3: Distributor has no Range Selector support >>>> [ 0.000000] Unable to handle kernel paging request at virtual >>>> address 000000000000ffe8 >>>> [ 0.000000] Mem abort info: >>>> [ 0.000000] ESR = 0x96000004 >>>> [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits >>>> [ 0.000000] SET = 0, FnV = 0 >>>> [ 0.000000] EA = 0, S1PTW = 0 >>>> [ 0.000000] Data abort info: >>>> [ 0.000000] ISV = 0, ISS = 0x00000004 >>>> [ 0.000000] CM = 0, WnR = 0 >>>> [ 0.000000] [000000000000ffe8] user address but active_mm is >>>> swapper >>>> [ 0.000000] Internal error: Oops: 96000004 [#1] SMP >>>> [ 0.000000] Modules linked in: >>>> [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc1 #5 >>>> [ 0.000000] pstate: 20000085 (nzCv daIf -PAN -UAO) >>>> [ 0.000000] pc : gic_iterate_rdists+0x58/0x130 >>>> [ 0.000000] lr : gic_iterate_rdists+0x80/0x130 >>>> [ 0.000000] sp : ffff8000113d3cb0 >>>> [ 0.000000] x29: ffff8000113d3cb0 x28: 0000000000000000 >>>> [ 0.000000] x27: 0000000000000000 x26: 0000000000000018 >>>> [ 0.000000] x25: 000000000000ffe8 x24: 000000000000003f >>>> [ 0.000000] x23: ffff800010588040 x22: 00000000000005e8 >>>> [ 0.000000] x21: ffff8000113df7d0 x20: 0000030f00003f11 >>>> [ 0.000000] x19: 0000000000000000 x18: ffffffffffffffff >>>> [ 0.000000] x17: 0000000014aeb8dc x16: 00000000c3ba0ccf >>>> [ 0.000000] x15: ffff8000113d9908 x14: ffff8000913d3a37 >>>> [ 0.000000] x13: ffff8000113d3a45 x12: ffff800011402000 >>>> [ 0.000000] x11: ffff8000113d39d0 x10: ffff8000113db980 >>>> [ 0.000000] x9 : 00000000ffffffd0 x8 : ffff8000106dca98 >>>> [ 0.000000] x7 : 000000000000005b x6 : 0000000000000000 >>>> [ 0.000000] x5 : 0000000000000000 x4 : ffff8000128c0000 >>>> [ 0.000000] x3 : ffff8000128a0000 x2 : ffff0003fc3c7000 >>>> [ 0.000000] x1 : 0000000000000001 x0 : 000000000000ffe8 >>>> [ 0.000000] Call trace: >>>> [ 0.000000] gic_iterate_rdists+0x58/0x130 >>>> [ 0.000000] gic_init_bases+0x200/0x4b4 >>>> [ 0.000000] gic_acpi_init+0x148/0x284 >>>> [ 0.000000] acpi_match_madt+0x4c/0x84 >>>> [ 0.000000] acpi_table_parse_entries_array+0x188/0x278 >>>> [ 0.000000] acpi_table_parse_entries+0x70/0x98 >>>> [ 0.000000] acpi_table_parse_madt+0x40/0x50 >>>> [ 0.000000] __acpi_probe_device_table+0x88/0xe4 >>>> [ 0.000000] irqchip_init+0x38/0x40 >>>> [ 0.000000] init_IRQ+0x168/0x19c >>>> [ 0.000000] start_kernel+0x328/0x508 >>>> [ 0.000000] Code: f90017b6 9b3a7f16 f8766853 8b190260 (b9400000) >>>> [ 0.000000] ---[ end trace ae5cf232d924bfc1 ]--- >>>> [ 0.000000] Kernel panic - not syncing: Fatal exception >>>> [ 0.000000] Rebooting in 3 seconds.. >>>> >>>> In this case, nr_redist_regions counts all GICC structures but only >>>> enabled ones have redistributor mapped. So add check to avoid NULL >>>> deference of redist_base. >>>> >>>> Signed-off-by: Heyi Guo <guoheyi@huawei.com> >>>> Cc: Thomas Gleixner <tglx@linutronix.de> >>>> Cc: Jason Cooper <jason@lakedaemon.net> >>>> Cc: Marc Zyngier <maz@kernel.org> >>>> --- >>>> drivers/irqchip/irq-gic-v3.c | 7 +++++++ >>>> 1 file changed, 7 insertions(+) >>>> >>>> diff --git a/drivers/irqchip/irq-gic-v3.c >>>> b/drivers/irqchip/irq-gic-v3.c >>>> index d6218012097b..bd9d55cadef9 100644 >>>> --- a/drivers/irqchip/irq-gic-v3.c >>>> +++ b/drivers/irqchip/irq-gic-v3.c >>>> @@ -781,6 +781,13 @@ static int gic_iterate_rdists(int (*fn)(struct >>>> redist_region *, void __iomem *)) >>>> u64 typer; >>>> u32 reg; >>>> >>>> + /* >>>> + * redist_base may be NULL if we use single_redist and >>>> some GICC >>>> + * structure is disabled. >>>> + */ >>>> + if (!ptr) >>>> + continue; >>>> + >>>> reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK; >>>> if (reg != GIC_PIDR2_ARCH_GICv3 && >>>> reg != GIC_PIDR2_ARCH_GICv4) { /* We're in trouble... */ >>> >>> This feels like the wrong fix. The redistributor region array should >>> be completely populated, and there is an assumption all over this >>> driver >>> that there is no junk in these structures. >> >> >> Oh, I thought the place holder for disabled GICR in nr_redist_regions >> were for some special reason, like CPU hotplug. Now I know I was wrong >> :) > > CPU hotplug would imply that the redistributors are available. > My interpretation of the ACPI MADT GICC subtable is that the > redistributors are simply inaccessible when disabled. > > Otherwise, it'd be legitimate to just map them and live with > redistributors that do not have a corresponding CPU (which we > otherwise do). See ebe2f8718007 for details. > > If we need to support redistributors becoming enabled under our > feet, then we'll have to handle this in a different way. We're > not there yet. Got it. > >>> You're seeing this because we don't track the number of *enabled* >>> rdists, >>> and allocate the number of regions based on the number of overall GICC >>> entries instead of the number of enabled redistributors. >>> >>> How about this instead? >> >> It looks good to me, and works fine in my case. > > Can I take this as a Tested-by: ?
Sure.
Tested-by: Heyi Guo <guoheyi@huawei.com>
Thanks,
Heyi
> > Thanks, > > M.
|  |